Changing complex behaviors such as tax evasion may require several behavioral interventions, or nudges. We developed a tailored compound intervention approach to increase employers’ payroll tax compli-ance in Estonia’s construction industry. First, we used anthropological methods to gain insights into the deci-sion processes of employers and employees in the industry (Study 1, N=16). These insights were combined with behavioral decision-making principles to design an intervention e-mail with the aim to strengthen per-ceived risks and weaken descriptive norms of non-compliance as well as to strengthen collaborative and weaken adversarial construal of tax authority. The compound intervention was tested using a three-armed non-blinded randomized controlled trial (Study 2, N=4770) involving all employers whose declared wages were below 70% of the industry’s average. The intervention significantly increased declared payroll taxes by 5.1% to 6.1% on average across the two treated groups over a 3-month follow-up period (p< .0001) and was therefore effective. It remains unclear which constituent nudges of our compound intervention were crucial for this effect. These findings suggest that the compound intervention approach may be a feasible avenue for designing effective interventions in under-studied contexts.